As the demand increases for varying types of applications within mobile telecommunications networks, service providers must constantly upgrade their systems in order to reliably provide this expanded functionality. What was once a system designed simply for voice communication has grown into an all-purpose network access point, providing access to a myriad of applications including text messaging, multimedia streaming, and general Internet access. As seen in second and third generation networks, voice services must be carried over dedicated voice channels and directed toward a circuit-switched core, while other service communications are transmitted according to the Internet Protocol (IP) and directed toward a different, packet-switched core. This led to unique problems regarding application provision, metering and charging, and quality of experience (QoE) assurance.
In an effort to simplify the dual core approach of the second and third generations, the 3rd Generation Partnership Project (3GPP) has recommended a new network scheme it terms “Long Term Evolution” (LTE). In an LTE network, all communications are carried over an IP channel from user equipment (UE) to an all-IP core called the Evolved Packet Core (EPC). The EPC then provides gateway access to other networks while ensuring an acceptable QoE and charging a subscriber for their particular network activity.
The 3GPP generally describes the components of the EPC and their interactions with each other in a number of technical specifications. Specifically, 3GPP TS 29.212, 3GPP TS 29.213, and 3GPP TS 29.214 describe the Policy and Charging Rules Function (PCRF), Policy and Charging Enforcement Function (PCEF), and Bearer Binding and Event Reporting Function (BBERF) of the EPC. These specifications further provide some guidance as to how these elements interact in order to provide reliable data services and charge subscribers for use thereof.
For example, 3GPP TS 29.212, 29.213, and 29.214 specifications provide some guidance on reporting events between the PCRF and the PCEF or BBERF. 3GPP TS 29.212 defines several event triggers that the PCRF may provision to request that the PCEF or BBERF to report an event when it occurs. For example, the PCRF might provision a RE VALIDATION_TIMEOUT event trigger to the PCEF to indicate the end of a session. The PCEF would then report to the PCRF when a revalidation timeout has occurred.
The 3GPP standards, however, provide little guidance about how the PCRF should respond to events. For example, the specifications provide that the PCRF may provide a new value for the revalidation timeout, but do not indicate how to determine a new value. Methods using fixed absolute values could be used to respond to all events but would limit the variety of options available.
In view of the foregoing, it would be desirable to provide a Policy and Charging Rules Node (PCRN) implementing a PCRF capable of responding to network events on a per subscriber basis or per session basis. In particular, it would be desirable for the PCRN to respond to revalidation timeout events so that some subscribers may extend their sessions.